As disclosed in U.S. Pat. No. 4,984,992, an electrical connector comprises, an insulative housing block, electrical contacts spaced apart along the housing block, and wire connecting portions of the contacts constructed for being overlaid by corresponding electrical wires and for being welded to the corresponding wires by welding electrodes of a welding apparatus.
The wire connecting portion of each of the contacts is thin and flat, having been cut from a sheet of metal. The wire and the wire connecting portion are clamped between the electrodes during the welding operation. It is important to maintain the wire in position with respect to the wire connecting portion prior to being clamped by the electrodes. If the wire is dislodged from its position, the wire can be connected ineffectively, or not at all, to the wire connecting portion.
Although the wire connecting portion is capable of being connected to wires of both solid wire construction and stranded wire construction, it is the stranded wire construction that is more difficult to maintain in position with respect to the wire connecting portion. A stranded wire, a wire having multiple wire strands, is limp and less stiff than a solid wire, and is more apt to be dislodged from its position with respect to the wire connecting portion. The strands tend to unravel and would lack confinement within a weld joint formed between the wire and the electrical contact.
According to U.S. Pat. No. 4,690,647, to hold a wire in position, an electrical contact is formed with upturned portions that grip the wire. Although such a construction effectively grips the wire, the upturned portions are not readily adapted for welding by electrodes. The upturned portions would deform under electrical current and pressure, applied by the electrodes during a welding operation, which could render the welding operation ineffective, or which could require the welding operation to vary unless the welding operation were skillfully performed to account for variations in the deformity resulting from the applied electrical current and pressure.